磷尾矿是磷矿选矿后产生的固体废弃物，其主要成分为白云石。磷尾矿的高价值组分较少，难以利用，长期大规模堆存不仅占用土地，污染土壤而且易造成资源浪费。针对磷尾矿化学成分的特点，对其进行焙烧处理，焙烧过程使磷尾矿孔隙度增加，扩大了产品比表面积，提升了其反应活性。结果表明，在900 ℃、60 min的最佳焙烧条件下，磷尾矿烧失率为36.76%，产品中碳酸盐质量分数为5.76%。此时，产品中CaO和MgO质量分数分别为53.00%和29.39%，主要物相为CaO、MgO和SiO₂。磷尾矿在上述条件下焙烧后分解较为彻底，主要物相转变为氧化钙镁，可以用于氨氮废水处理。在磷尾矿焙烧产物用量为160 g/L的条件下，废水氨氮质量浓度由1 000.0 mg/L降低至143.8 mg/L，去除率为85.62%，剩余氨氮浓度满足后续生化处理工艺的要求。研究结果可为磷尾矿焙烧条件和磷尾矿焙烧产物处理氨氮废水提供一定的理论指导。

Phosphorus tailings are solid wastes produced after phosphorous ore beneficiation，the main component of which is dolomite.Phosphorus tailings contain less high-value components，which is difficult to use.Long-term and large-scale storage not only occupies land，pollens soil，but also causes resource waste.In this study，the phosphorus tailings were calcined according to their chemical composition characteristics，the calcination process increased the porosity of the phosphorus tailings，enlarged the specific surface area of the product，and improved its reactivity.The results showed that under the optimal roasting condition of 900 ℃ and 60 min，the phosphorus tailings' burning loss rate was 36.76%，with a carbonate content of 5.76% in the product.At this point，the content of CaO and MgO in the product was 53.00% and 29.39% respectively，with the main phases of CaO，MgO，and SiO₂.After roasting under the above conditions，the decomposition of phosphorus tailings was more thorough，and the main phase was transformed into calcium and magnesium oxide，which could be used for ammonia nitrogen wastewater treatment.Under the conditions of 160 g/L dosage，the concentration of ammonia nitrogen in wastewater was decreased from 1 000.0 mg/L to 143.8 mg/L，with a removal rate of 85.62%，the remaining ammonia nitrogen concentration met the subsequent biochemical requirements.The research results could provide some theoretical guidance for the roasting conditions of phosphorus tailings and the treatment of ammonia nitrogen wastewater by the products of phosphorus tailings roasting.